AudioCircle

Audio/Video Gear and Systems => Open Baffle Speakers => Topic started by: Poultrygeist on 8 May 2012, 11:59 am

Title: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 8 May 2012, 11:59 am
I finished these this past weekend and wow, what a big lively sound and more detail than I expected from a 12 inch.
(http://www.audiocircle.com/image.php?id=62369)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 8 May 2012, 12:14 pm
I've never been able to get a decent finish on MDF so my solution here was textured wallpaper which I painted. Up close it looks like leather. At 98dbs the Betas play loud and move lots of air. Very dynamic, well suited to a variety of music and affordable.


(http://www.audiocircle.com/image.php?id=62370)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: JohnR on 8 May 2012, 12:19 pm
Looks nice, what tweeter is that?
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 8 May 2012, 12:27 pm
JohnR,

The tweeter is a Peavey that was on sale at PE.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: jagtek on 10 May 2012, 12:59 am
Nice job !
  I just finished some Hammer super 12 clones using the same driver.
They sound really good.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 10 May 2012, 01:52 am
I like your super 12 clones. Have you considered cutting off the dust cap and adding a phase plug? It's said to really smooth out the Beta.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Gothover on 10 May 2012, 05:18 am
Speaker looks great, nice work.

Dave
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 22 May 2012, 11:46 am
I'm now driving the super tweeters with their own t-amp.

(http://www.audiocircle.com/image.php?id=62886)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 22 May 2012, 12:01 pm
I added these phase plugs to the Betas and the improvement was quite significant. They now seem as smooth as the Tang Bands which are relegated to the closet for the time being.

(http://)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: nicoch on 24 May 2012, 05:18 pm
I added these phase plugs to the Betas and the improvement was quite significant. They now seem as smooth as the Tang Bands which are relegated to the closet for the time being.

Wow ! sure ? will be great news....

Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: RCduck7 on 24 May 2012, 06:23 pm
Very nice! So are these better then your under 300$ project on "cheap & cheerful"? http://www.audiocircle.com/index.php?topic=101222.0
It seems you have fun on building and have very good sound for little money in the process. But if you would plan a next project, why not something a little more extravagent? I have read on this forum that the AE IB15 driver is far superior then the Alpha 15 for instance from someone his experience...
http://www.aespeakers.com/drivers.php?driver_id=8
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 24 May 2012, 09:09 pm
IMO the Beta/H-frame Alphas sound better than my Betsy/Flat baffle Alphas but they cost a little more.

The Alpha 15A's in H-frames offer fast bass transients and sound nothing like a plodding sub. I prefer them as they are full range bass drivers with high Qts. ( 1.26 ) and high efficiency ( 97db ). Martin J. King, who has forgotten more than I'll never know about open baffles likes them as well.

http://www.quarter-wave.com/
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: ttan98 on 25 May 2012, 01:07 pm
Nice work, what about the phase plug on the Beta, does it look a little vulgar?
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 25 May 2012, 05:46 pm
Do these look better? :D

(http://www.audiocircle.com/image.php?id=63028)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: nicoch on 25 May 2012, 06:03 pm
IMO the Beta/H-frame Alphas sound better than my Betsy/Flat baffle Alphas but they cost a little more.

HI Poultrygeist ,thanks  but respect  the TB w8-1808? (this is not cheaper like Betsy)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 25 May 2012, 06:41 pm
The Beta's sound different but not better than the Tang Band W8-1808's. The flexibility of using the same H-frames allows me to change out just the tops and I expect to go back and forth between the Betas and Tang Bands.

I'll be building another pair of H-frames to stack or to use in my garage as I have an extra pair of Alphas.

The Betsy's I have use an early run of hemp cones ( per WB Labs info ) and although they lack the big sound of the Beta's my enthusiasm for them has not waned in the least. The folding wing Betsy's hooked me on OB's and I'm forever grateful for them and the Darkstar odyssey.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: nicoch on 25 May 2012, 07:04 pm
 :) the first love....

btw great work ! and good info, like the alpha work different /better on H frame ....

   



Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 26 May 2012, 01:18 pm
The phase plugs are nothing more than $.99 wooden Easter eggs from a local craft store ( AC Moore ). They are not true egg shaped as they have a flat bottom which allows them to sit on a base which I used in the first pictured phase plug. The added base extends their length more than is necessary. I countersunk some screws in the egg's flat bottom which holds them in place magnetically. I have some pictures of an easy procedure to cut off dust caps on another forum.

I don't know how many of you have tried OB but for me it was an epiphany. I've owned some well respected commercially made speakers such as Aerial Acoustics and Zu's but they just don't come close to what I get from these humble home spun OB's.

I can't multi-task in the same room while they're playing as I lose my train of thought and totally forget what I'm doing. If you like to read with music in the background these OB's may not be a good choice. Like a drug they take me somewhere else.

Anyone contemplating this build shouldn't think twice. They are so worth the modest effort.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 17 Jul 2012, 03:29 pm
Here are the Easter egg phase plugs I picked up at a local craft store. I screwed wood screws in their flat base so they would magnetically attach. The highs on the Betas have really smoothed out. I love OB and can't see myself building anything else. Nothing compares and I don't care if I'm preaching to the choir.


(http://www.audiocircle.com/image.php?id=65271)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 17 Jul 2012, 03:37 pm
They look almost sexy in low light.  :lol:

(http://www.audiocircle.com/image.php?id=65272)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: this_is_vv on 17 Jul 2012, 03:57 pm
i am making one now...
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 17 Jul 2012, 07:24 pm
cool!
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: this_is_vv on 29 Jul 2012, 01:54 am
As promised made one...will slowly make it close to you...this is just start point...


(http://www.audiocircle.com/image.php?id=63727)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 29 Jul 2012, 11:26 am
Great job and tell us more.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 2 Aug 2012, 02:43 pm
VV,

I know that you are also buying the Beta 12LTA and predict that as good as the small TBs sound you will like the Betas better.

After living with the 12 inch Betas for a few months my 8 inch TB W8-1808 tops are in the closet. The huge sound stage has won me over.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 9 Aug 2012, 07:04 pm
FWIW here is a review of two of the three amps I use to power these OBs.

http://www.tnt-audio.com/ampli/dayton_apa150_e.html
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: this_is_vv on 12 Aug 2012, 05:59 am
FWIW here is a review of two of the three amps I use to power these OBs.

http://www.tnt-audio.com/ampli/dayton_apa150_e.html

Nice review but wanted to make rue we can use any 100w amp for bass...if someone wants to save money they can use something like what you got a receiver that can be used as amo
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Russell Dawkins on 12 Aug 2012, 08:32 am
FWIW here is a review of two of the three amps I use to power these OBs.
http://www.tnt-audio.com/ampli/dayton_apa150_e.html

Interesting how Linn Audio of New Hampshire sells the Dayton 150 as the LANH 150 for $1950.

(http://www.audiocircle.com/image.php?id=66356)
Dayton 150, $128-210

(http://www.audiocircle.com/image.php?id=66357)
LANH 150, $1950

I checked the Linn website and saw a Behringer A500 being sold as the LANH 500 for $3500. This Behringer sells for $222.34 at Amazon.

You really can't mistake the appearance of the Behringer!

(http://www.audiocircle.com/image.php?id=66354)
Behringer A500, $222.34

(http://www.audiocircle.com/image.php?id=66355)
LANH 500, $3500

As with the Dayton, not all of the silk screening is removed. In the case of the Dayton, their logo was even left in place, and it looks like the Behringer trademark with the ear in a triangle is still on the central meter!



Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Mijknarf on 13 Aug 2012, 01:23 am
Mr. Poultrygeist... +1 as a believer!

(http://www.audiocircle.com/image.php?id=66379)

(http://www.audiocircle.com/image.php?id=66380)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Russell Dawkins on 13 Aug 2012, 02:04 am
Mijknarf, may I suggest you think long and hard before covering that ceiling up with drywall or anything hard. I had a low ceiling in my last basement listening room and it sounded great when the pink fiberglass was exposed like that - and not nearly as good after I had installed a double layer of drywall suspended from the joists above. If you are be concerned about falling glass fibers, you could cover it with plastic before whatever you decide to use as a covering, presuming it's some kind of fabric, or otherwise porous.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: studiotech on 13 Aug 2012, 02:49 am
Interesting how Linn Audio of New Hampshire sells the Dayton 150 as the LANH 150 for $1950.

(http://www.audiocircle.com/image.php?id=66356)
Dayton 150, $128-210

(http://www.audiocircle.com/image.php?id=66357)
LANH 150, $1950

I checked the Linn website and saw a Behringer A500 being sold as the LANH 500 for $3500. This Behringer sells for $222.34 at Amazon.

You really can't mistake the appearance of the Behringer!

(http://www.audiocircle.com/image.php?id=66354)
Behringer A500, $222.34

(http://www.audiocircle.com/image.php?id=66355)
LANH 500, $3500

As with the Dayton, not all of the silk screening is removed. In the case of the Dayton, their logo was even left in place, and it looks like the Behringer trademark with the ear in a triangle is still on the central meter!

This really pisses me off!

Greg
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: this_is_vv on 13 Aug 2012, 04:06 am
Mr. Poultrygeist... +1 as a believer!

(http://www.audiocircle.com/image.php?id=66379)

(http://www.audiocircle.com/image.php?id=66380)


i just loved your speaker...this is what i should be making now...beautiful...hows the sound u like??

V
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Mijknarf on 13 Aug 2012, 05:07 am
V:  Thanks for the feedback. Their sound is large, open, and as full range as I've ever known.  Stereo separation is wide yet imaging is really good.  This is the first time I've used a tweeter in 5+ years, so it has taken some getting use to.  Uber detail is not a strength of the 12LTA drivers, but the trade off for big/dynamic sound stage is worth it.

Russell: Great point and I appreciate the input.  I'm planning on a suspended ceiling, not drywall.  I was wondering what the change in acoustics would do. I need to ponder the next move carefully...

Poultrygeist:  Thanks for all the input and feedback, you were a big help!
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Russell Dawkins on 13 Aug 2012, 05:38 am
With a suspended ceiling (I'm assuming you would be using "acoustic tile") I think you would hear a slight degradation compared to what you are hearing now (it must be pretty good with nice clean bass!) since there would be a degree of reflection of the upper mids and highs that you are not getting now. The most important characteristic should stay intact, though, - or even improve - and that is the bass absorption.  I do think it would be your best conventional option.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: this_is_vv on 13 Aug 2012, 05:40 am
V:  Thanks for the feedback. Their sound is large, open, and as full range as I've ever known.  Stereo separation is wide yet imaging is really good.  This is the first time I've used a tweeter in 5+ years, so it has taken some getting use to.  Uber detail is not a strength of the 12LTA drivers, but the trade off for big/dynamic sound stage is worth it.

Russell: Great point and I appreciate the input.  I'm planning on a suspended ceiling, not drywall.  I was wondering what the change in acoustics would do. I need to ponder the next move carefully...

Poultrygeist:  Thanks for all the input and feedback, you were a big help!

so i see lot of tube amps...whats the crossover active or passive...?..also can you take a back pic of top ...
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Mijknarf on 13 Aug 2012, 02:41 pm
Bass is run from stereo 250 watt plate amps low pass set at 175Hz (use a 6.4mH coil).
12LTA and tweeter run from a 2A3 SET amp.  12LTA straight from amp and I use a 1.0uF cap on the tweeter.

A question for anyone... Should I connect the tweeter and 12LTA in parallel or series?  Parallel would show a 4 ohm load to the amp, series would show a 16 ohm load, correct?  Not sure where I need to be.  Any advice would be appreciated.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 13 Aug 2012, 09:28 pm
Mijknarf,

As I told you in the PM those puppies are just drop dead gorgeous.  :thumb:

Dang if you didn't stain the Easter egg phase plugs to match the rest of the wood.

I wish you could bring them with you when you travel south.

Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Mijknarf on 14 Aug 2012, 02:16 am
Thanks Paul.

As an answer to my question above regarding wiring, I ended up putting the drivers in series and used the 16 ohm tap on my James OPT. 
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: this_is_vv on 23 Aug 2012, 03:35 am
what kinda wires do one use to connect the speaker terminal to the binding post... i am using this...is it too heavy?

http://www.monoprice.com/products/product.asp?c_id=102&cp_id=10239&cs_id=1023902&p_id=2748&seq=1&format=2

any inputs


V
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: mor2bz on 23 Aug 2012, 03:52 am
Not correct: load will still be 8 ohms when wired in parallel

looks like a great setup.  Owens Corning has dense fibreglass panels
for ceilings if you do not want to lose your absorption.

Wouldn't a beta 15 go low enough for you in the bass h frames and
deliver tighter bass?  I have them and they don't go low enough in a panel
but I bet they do great in a H frame.

best of luck

Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 11 Sep 2012, 06:33 pm
I'm testing the Bohlender Graebener planar teeters and so far so good. Driving them with their own t-amp and I'm sure I have them padded down way too much. They sound so airy it's scary :D

(http://www.audiocircle.com/image.php?id=67569)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 11 Sep 2012, 06:42 pm

(http://www.audiocircle.com/image.php?id=67570)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 11 Sep 2012, 06:54 pm

(http://www.audiocircle.com/image.php?id=67571)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: this_is_vv on 11 Sep 2012, 07:19 pm
i like what i see....worth the investment so far?....whats the frequency u have crsossed it to??


V
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: this_is_vv on 13 Sep 2012, 08:54 pm
(http://www.audiocircle.com/image.php?id=67571)

Paul,

Any updates???


V
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 15 Sep 2012, 05:08 am
V,

I've got an order coming from PE and so far I'm experimenting with a simple first order. Everything I try sounds great.  These are the best tweeters I've ever heard.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 21 Sep 2012, 01:22 am
I relocated the tweeters so that nothing obstructs their rear waves. With the Neo3 there's alot more going on up there than shimmering cymbals.   :thumb:

(http://www.audiocircle.com/image.php?id=68106)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Russell Dawkins on 21 Sep 2012, 01:55 am
It probably helps a little not to have those parallel surfaces of the supports so close to the rear aperture, too. The standing wave across that 2.5" or so would create a sound of its own.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 21 Sep 2012, 11:28 am
So how would you mount them?
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Russell Dawkins on 21 Sep 2012, 04:35 pm
Well I'm saying that the rear reflection consideration is probably moot now that you have the tweeter mounted as it is now, but if you wanted a sturdier mount like the first, I would bevel the insides of the small (3/4" X 3/4"?) uprights and/or attach some kind of absorption like foam or felt to the inside surfaces.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 2 Oct 2012, 01:29 am
This single post mount seems to work fine.


(http://www.audiocircle.com/image.php?id=68746)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 2 Oct 2012, 01:31 am

(http://www.audiocircle.com/image.php?id=68747)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: this_is_vv on 2 Oct 2012, 03:16 am
(http://www.audiocircle.com/image.php?id=68747)

hows ur review for the entire system now?


V
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 2 Oct 2012, 12:14 pm
These are the best speakers I've ever owned and far more enjoyable than the Zu's and Aerial Acoustics I sold not long ago. Beside their huge sound stage their key attribute is how the music sounds so "live". This is a worn out adjective with open baffles but it's still the best way to describe it.

I often listen to MJQ and am blown away by the way the Neo3s float notes from Milt's vibes...almost like soap bubbles of sound hanging in mid-air I could reach out and touch.

I'm running the Betas full range straight off the amp without any correction in the signal path and love the sound I'm getting. I believe the mods and phase plug addition have made the difference. BSC as I understand it is also amp and room dependent.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 15 Oct 2012, 12:51 pm
I am trying a Behringer electronic crossover with the Betas and Neo 3s and so far so good. The two Dayton amps are driving and controlling the Alphas independently with their built in crossovers.

(http://www.audiocircle.com/image.php?id=69391)

Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 15 Oct 2012, 12:59 pm
The Daytons are on the floor.

(http://www.audiocircle.com/image.php?id=69392)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: this_is_vv on 15 Oct 2012, 03:22 pm
Seems like you like Electronic crossover....i cant imagine working without it anymore....

Good stuff...

V
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 21 Oct 2012, 11:15 pm
The active crossover makes it so much easier to integrate the 3 ways. I just picked up a new Behringer CX3400 3 way off ebay for $119.

I'm looking hard at the Yung Class D plate amps at PE to replace the Dayton APA150's.

Small, powerful, quiet and cool running are great features of class D plate amps.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: LynX on 22 Oct 2012, 09:08 am
I would also agree that active crossovers make a huge difference. However, I would like to say that I have the cx3400 currently in my setup and am smothered with quality problems. For instance left channel mid looses proper output until warmed up and then works correctly. The limiter feature kicks on as a hard clip instead. The adjustments are not very accurate. The list goes on. As far as the good; it sure does come with a lot of features for very little money. And it does work good and sound pretty well. Spending some extra money with better reliability would be a good idea.
When the cx3400 was new I had no problems with it whats over, but after  a year a whole bunch of problems started to show up. Good but still inexpensive choices are dbx 234, rane ac22 or 23, etc.
Not trying to bash any ones gear but spending a little more might last you and serve you better in the long run. I sure do wish I could have made the right choice the first time.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 22 Oct 2012, 11:46 am
Yes, from what I've read Behringer xo'ers can have issues and aren't long lived. You can also read about issues with other pro-audio actives such as Rane and dbx as well. I hope to use the $119 CX3400 as a transition piece to a Marchand.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: same64 on 29 Oct 2012, 09:58 am
Hi

Did anybody took the measument how low 12LTA goes on the baffle?.
I've set 250-300 hz on my miniDSP .
I was looking at the Yung plate  but it goes only up to 200hz .And if the 12LTA dont go that low than is not optimum.
At them moment im running tubes on hights and old NAD on lowes.

my build below.
(http://www.audiocircle.com/image.php?id=70040)





Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 29 Oct 2012, 11:33 am
Nice build my friend.

Replacing the dust cap with a phase plug will smooth out the highs on the 12LTA.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: same64 on 8 Nov 2012, 09:39 am
Hi
Still bit worried about the surgery:-)
I must say i do enjoy OB a lot. And wondering what else i can do to improve them even more.



Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 8 Nov 2012, 01:02 pm
I really like the B&G Neo 3 tweeter and I just swapped out the Daytons with two Yung SD300 plate amps.

Removing the dust caps is easier than you think. The raised ridge keeps the exacto blade on track. It would be hard to mess up.

The ebay seller reneged on the 3 way Behringer crossover so I bid and won a Rane 3 way. Looking forward to giving it a go.



Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 8 Nov 2012, 01:23 pm
Here are the Yung plate amps with the garage OBs. Nice tight detailed bass with the Alphas.

(http://www.audiocircle.com/image.php?id=70550)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: same64 on 1 Jan 2013, 03:01 am
How is the B&G Neo 3 tweeter experiment going?.

 regards

Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Guy 13 on 1 Jan 2013, 03:25 am
Here are the Yung plate amps with the garage OBs. Nice tight detailed bass with the Alphas.

(http://www.audiocircle.com/image.php?id=70550)
Hi Poultrygeist and all Audio Circle members.
The shelves packed with all sort of (useful) things must act as a good diffuser?
Guy 13
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 1 Jan 2013, 12:24 pm
The Neo 3's are a delight. I now use the 2 way Behringer CX2310 for just the Neo 3's ( high ) and the Beta's ( low ) by selecting the x10 frequency on the back. The plate amps control the Alpha's with their crossover settings. I use a single cap on the Neo 3's for protection and drive it with a Topping T-21 tripath amp.

I tried a Behringer 3 way but returned it to PE as the cheaper 2 way is better IMO. The Rane I bought off ebay was DOA and I got a refund. Lesson learned - used pro-audio gear can mean "rode hard and put up wet".
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 1 Jan 2013, 12:40 pm
same64,

Here is the easy removal of the 12LTA dust cap with an Exacto blade. The inner lip keeps the cut on line and mistake free. I'm using a Lazy Susan ( remember those? ) to spin the driver but it's not necessary. I gradually sliced deeper with each turn.
 
(http://www.audiocircle.com/image.php?id=73105)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 1 Jan 2013, 12:50 pm
After a few revolutions with the Exacto blade held stationary the dust cap comes right out. I've performed lots of dust cap surgeries but this is the easiest one yet and it takes the Beta to a new level especially with the wooden egg phase plugs. FWIW I used 4 screws in the base of the phase plugs ( picture in this thread only shows 2 ).

(http://www.audiocircle.com/image.php?id=73106)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 1 Jan 2013, 12:58 pm
Prying off the rear cover of the Bohlender Graebener Neo 3 so it can be used in an open baffle. An old dull smooth blade knife works well for this.

(http://www.audiocircle.com/image.php?id=73107)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 1 Jan 2013, 01:06 pm
This is the gear I use with the Beta 12LTA's over H-frame Alpha's

(http://www.audiocircle.com/image.php?id=73108)
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: same64 on 2 Jan 2013, 08:53 am
have you tried minidsp?.i never used Behringer crossover so cant coment but Minidsp is really good.http://www.minidsp.com/
At moment i have  only two way but will get one more to run as 3 or even 4 way if i like.
Just finished TH2050 mulltichannel power amp ,that makes much user friendly instead of running few amps .
Next B&G Neo 3:-)



Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 2 Jan 2013, 02:52 pm
I know the Minidsp would probably be an upgrade over the analog Behringer but I like having controls to make adjustments on the fly. I'm not sure that's possible with the Minidsp but perhaps I wouldn't feel the need to if I had one??? I don't even have a handle on what points I'm actually using as I adjust by ear and the control markings are vague.

I've also read that the gentle 12 db slope was preferred over the steeper 24 db slopes on systems such as this. The Pioneer electronic crossovers from the 70's and early 80's which use the gentler slopes are grabbed up fast on ebay. One member on AK uses one of the vintage Pioneer crossovers with his expensive Lowther based OB's.

I'm just getting my feet wet with electronic crossovers and have much to learn. I'd love to know more about the Behringer DCX2496 and might consider it but the Red Spade audio site said it's not a good match with tube preamps??? But others have said it is?
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: frperdurabo on 13 Jan 2013, 08:49 pm
I used the Behringer about ten years ago and thought it sounded pretty "digital" ie, hard, glassy, fatiguing.   OK for prototyping but not to live with long term.  YMMV, obviously, and of course ten years is a lifetime for digital products - new ones may be much improved.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 13 Jan 2013, 11:19 pm
Yesterday my friend listened to my system and gave nothing but high praise. I trust his ear as it puts bread on his table as he's a pro violinist with the SC and Charlotte Phil. He's also an amp builder with some fine gear. We momentarily tried the Miniwatt SET on the Neo 3's but it ran out of gas. I'm now driving the Neo 3's with a Dayton DTA-100 which seems better than the less powerful Topping.

Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Russellc on 15 Jan 2013, 06:53 pm
Say, wondering about the sensitivity of the bass and full range drivers compared to the planer tweeter.
Specs for the bass and mid are an identical claim of 97 dB, 1w/1m, whereas the planer tweeter is only 90 dB, but measured 2.83v/1m instead of the 1w/1m of the other two drivers.  Do these 2 different measurements make it look this different, (90 dB vs 97 db) and if measured the same would be closer, or are you turning down the sensitivity of the full range/bass units via electronic crossover?

Russellc
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: this_is_vv on 15 Jan 2013, 08:16 pm
Say, wondering about the sensitivity of the bass and full range drivers compared to the planer tweeter.
Specs for the bass and mid are an identical claim of 97 dB, 1w/1m, whereas the planer tweeter is only 90 dB, but measured 2.83v/1m instead of the 1w/1m of the other two drivers.  Do these 2 different measurements make it look this different, (90 dB vs 97 db) and if measured the same would be closer, or are you turning down the sensitivity of the full range/bass units via electronic crossover?

Russellc

If i may add...i had same setup....and the mid used to come so forward....now i have changed to Scan speak 18w as mid and Raal 140-15d as tweeter ./...now my tweeter is 95 and mid is 89db...so i had to manually adjust the gain to meet them at 90 and now everything comes on proper...though it feel like that the voice is little mellow down but now i understand the quality more clearly...

again humbly its my own opinion...

V
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 16 Jan 2013, 12:16 am
On the 2 way Behringer I turn up the gain on the neo3 ( high ) and dial back on the Beta output ( low ). The Betas play rather high anyway and the 4 ohm Neo's seem more efficient than their specs indicate ( I have both models ). With the Neo's high hats shimmer and float in space as if they're in the room.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Luigi on 16 Jan 2013, 07:47 pm
Hi Guys

My OB project is broadly similar, another take on a similar theme. Hope I'm not interloping here.

I'm using Hawthorne PSI 15 (which normally runs fully open in the Solo setting) and have a set of TAD drivers (2001s I think, from memory) that screw into the back of the PSI 15 so dual concentric arrangement.

Had been messing for a long time with series passive crossover but changed lately to miniDSP active crossover and instantly got better results (in half a day vs half a year of faffing with passives). By being able to reduce the output to the TADs I can get them to integrate more convincingly with the PSI 15s. The TADs had always seemed a bit sharp and I guess it was because they were just being more sensitive than the PSI 15s.

Im bringing the TADs in from about 2500Hz and letting the PSI 15s run to 5000. With LR24 slopes there's almost a straight line on the miniDSP crossover, with little in the way of dip at the point where the two slopes cross. I have no measuring equipment  so am doing everything by ear.

Just wondering whether I'm all at sea with crossover points. Would it be better to forsake the straight line on the miniDSP (ie, allow a dip where the two lines intersect) and let the Hawthorne stop at 2500, with the TADs taking over from there?

Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Luigi on 17 Jan 2013, 07:20 pm
With the miniDSP this is only a 10min job anyway so gave it a lash and the result is a clear improvement in intelligibility. I always thought that this was the area where you should try to avoid putting a crossover point. Whatever, the ears don't lie; when you can hear dialogue better at lower volumes, you're on the right track.
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Mmaxed on 14 Mar 2013, 12:39 am
Hey PG, I know you had posted it somewhere but I can't find it now.  I would like the dimensions of the baffle that the LTA is mounted in.  Also the location of the LTA.

Out of curiosity, how did you arrive at the placement in the baffle?
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 14 Mar 2013, 10:15 am
http://www.quarter-wave.com/Project08/Jordan.pdf
Title: Re: My new Beta 12LTA over H-frame Alpha build
Post by: Poultrygeist on 31 Mar 2013, 01:12 pm
I've found what I believe to be a better and cheaper tweeter match for the Beta 12LTA. These super horn tweeters once sold by Radio Shack have higher sensitivity and once removed from their plastic pod work very well in OB. The Realistic 40-1310A I use was made in Japan ( Fostex? ) and is not the same as the Korean made Radio Shack 40-1310B or Chinese made Radio Shack 40-1310C. Different design and different specs printed on the magnet. The "A" model has a different throat and does not look like the one pictured below.

http://diyaudioprojects.com/Drivers/40-1310/40-1310.htm